JP6343574B2 - catheter - Google Patents

Description

  The present invention relates to a catheter capable of a tip deflection operation.

An electrode catheter is known as a medical device used for diagnosing or treating cardiac arrhythmia. When the electrode catheter is inserted into the patient's body, the sheath catheter is first introduced into the body, and then the electrode catheter is inserted into the inner hole of the sheath catheter and advanced.

  In a catheter inserted through a blood vessel to the inside of the heart, it is required that the vicinity of the distal end be bendable with a predetermined curve shape in order to smoothly insert the inside of the blood vessel or the heart. For this reason, electrode catheters and sheath catheters are inserted into the body by pulling the pull wire inserted through the catheter with the operation unit attached to the proximal end (base end or proximal side) of the catheter disposed outside the body. The distal end (tip) of the catheter is deflected. Here, in the present application, a sheath catheter whose tip can be bent is called a steerable sheath.

  By the way, in a catheter that can be deflected (bent) by pulling the pull wire, not only the portion (tip) that is desired to be bent but the entire catheter may be tilted. As a countermeasure, a method of reinforcing the proximal end side of the catheter by inserting a SUS coil into a pull wire lumen is used (see Patent Document 1).

Japanese Patent Application Laid-Open No. 08-24341

  In a steerable sheath, it is necessary to ensure a sufficient size of a lumen for inserting an electrode catheter or the like, and on the other hand, since it is used by being inserted into a blood vessel, the outer diameter cannot be increased. Therefore, the wall thickness of the tube wall becomes extremely thin, and the lumen for the pull wire also becomes thin. Even if a structure in which a SUS coil is inserted into a pull wire lumen as described in Patent Document 1 is used for such a steerable sheath, a sufficiently large SUS coil cannot be used, and a sufficient effect can be obtained. Absent. Furthermore, since the strength of the reinforced portion is increased, there is a problem that the followability of the blood vessel is deteriorated.

  This invention is made | formed in view of such a subject, The objective is to provide the technique which can suppress the fall of the whole catheter at the time of a tip deflection | deviation operation, without reinforcing the proximal end part of a catheter.

  One embodiment of the present invention is a catheter. The catheter includes a flexible tubular member having a plurality of lumens formed along an axial direction, and an operation lumen disposed at a position out of a central axis of the tubular member among the plurality of lumens. An operation wire that is inserted and fixed at one end near the distal end of the tubular member, and is disposed along the central axis on the opposite side of the operation lumen with respect to the central axis. A bending suppression member that is inserted through the lumen, and has one end portion positioned on the proximal side by the length of the bending allowable region of the operation wire from the one end portion of the operation wire. Features. In the catheter, a distal end of the bending suppressing member is fixed to the tubular member, and a proximal end of the bending suppressing member is fixed to a handle provided on a proximal side of the tubular member. Also good.

  In the catheter of the aspect described above, the other end of the tubular member is inserted into another operating lumen disposed along the central axis on the side opposite to the operating lumen with respect to the central axis. Another operation wire fixed in the vicinity of the distal end, and disposed along the central axis on the opposite side of the other operation wire with respect to the central axis, and one end portion of the other operation wire There may be provided another bending suppression member positioned on the proximal side by the length of the bending allowable region of the other operation wire from the one end of the operation wire. In the catheter, a distal end of the other bending suppression member may be fixed to the tubular member, and a proximal end of the other bending suppression member may be fixed to the handle. In any one of the above-described aspects, a lumen may be provided in a region including the central axis along the central axis for allowing another catheter to pass therethrough.

  According to the present invention, it is possible to suppress the entire catheter from falling down during the tip deflection operation.

1 is a plan view of a catheter according to Embodiment 1. FIG. It is sectional drawing along the A'-A 'line | wire shown in FIG. It is sectional drawing of the front-end | tip part along the BB line shown in FIG. 6 is a plan view of a catheter according to Embodiment 2. FIG. FIG. 5 is a cross-sectional view taken along line A′-A ′ shown in FIG. 4. It is a figure which shows the method of evaluating the fall of the catheter when a pull wire is pulled.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(Embodiment 1)
FIG. 1 is a plan view of a catheter according to Embodiment 1. FIG. FIG. 2 is a cross-sectional view taken along line A′-A ′ of FIG. 3 is a cross-sectional view of the tip portion along the line BB shown in FIG.

  The catheter 10 according to the first embodiment is a catheter sheath used as an auxiliary instrument when the distal end of a catheter tube inserted into a blood vessel is installed at a desired indwelling destination. The catheter 10 is a single direction type in which the distal end portion can be deflected in one direction. As shown in FIG. 1, the catheter 10 includes a tubular member 20 and a handle 30.

  A handle 30 is attached to the proximal end of the tubular member 20. The handle 30 is equipped with a rotation operation unit 32 for performing a deflection operation (swing operation) of the distal end portion of the tubular member 20. The handle 30 and the rotation operation unit 32 constitute an operation unit. On the other hand, a ring-shaped fixing portion 70 made of a metal such as SUS is embedded in the distal portion of the tubular member 20, and the tip is tapered into the distal end of the tubular member 20. A tip tip 40 is attached.

  The tubular member 20 is a flexible tube, and the tubular member 20 is provided with a lumen 21 through which, for example, an electrode catheter can be inserted along the axial direction. For this reason, the tubular member 20 of this embodiment is a thin-walled tube. The outer diameter, inner diameter, thickness, and length of the tubular member 20 are, for example, 2.0 to 6.0 mm, 0.5 to 5.0 mm, 0.3 to 1.0 mm, and 600 to 1000 mm, respectively, and are tubular. By inserting the member 20 into the blood vessel, the blood vessel can be expanded. Examples of the material of the tubular member 20 include polyethylene, polyurethane, polyether block amide, polyester, and polyamide.

  In the tubular member 20, a first lumen (pull wire lumen) 22 and a second lumen 23 are formed along a central axis in a region outside the lumen 21. The first lumen 22 and the second lumen 23 are provided at symmetrical positions with the central axis of the tubular member 20 as the symmetry axis. The inner diameters of the first lumen 22 and the second lumen 23 are, for example, 0.2 to 0.6 mm.

  The pull wire (operation wire) 50 is inserted through the first lumen 22. The pull wire 50 is made of SUS wire, tungsten, Ni—Ti superelastic alloy, or the like, and has a diameter of, for example, 0.1 to 0.5 mm. The distal end of the pull wire 50 is fixed by welding to a fixing portion 70 installed at the distal portion of the tubular member 20. The proximal end of the pull wire 50 is connected to a known rotation operation portion 32 for performing a deflection operation of the bending allowable region (deflection region) D of the catheter tube 10. By operating the rotation operation unit 32, the pull wire 50 is pulled, and the bending allowable region D is bent in the direction A shown in FIG. 1, whereby the distal end of the catheter 100 is deflected. The length of the bending allowable region D is, for example, 80 mm.

  The bending suppression member 60 is inserted through the second lumen 23. For the bending suppression member 60, a wire strong against tensile load such as SUS wire, tungsten, Ni—Ti superelastic alloy is used, and the diameter thereof is, for example, 0.1 to 0.5 mm. The distal end of the bending suppressing member 60 is located on the proximal side by the length of the bending allowable region D from the position of the distal end of the pull wire, and is attached to the tubular member 20 by an adhesive or solder (not shown). It is fixed against. The method for fixing the distal end of the bending suppressing member 60 is not particularly limited, but a ring-shaped fixing portion 70 as shown in FIG. 3 may be prepared for the bending suppressing member 60 and welded. The proximal end of the bending suppressing member 60 is located in the handle 30 and is fixed to the handle 30 by an adhesive or solder (not shown). The bending suppression member 60 is stretched so as not to loosen.

  In the catheter 10 capable of bending operation, when the pull wire 50 is pulled, a contracting force is applied to the bending direction A side, and an extending force is applied to the opposite side of the bending direction. As a result, the catheter 10 is bent. More specifically, in the catheter 10, when the pull wire 50 is pulled, a force that contracts from the distal end to the proximal end of the tubular member 20 is applied on the bending direction A side. On the other hand, on the opposite side to the bending direction A side, the bending suppressing member 60 is inserted closer to the base end side than the bending region, and when the tubular member 20 tries to extend, tension is generated in the bending suppressing member 60. This tension limits the elongation of the tubular member 20 and suppresses bending. As a result, the region where the bending suppressing member 60 is inserted is suppressed from falling. Therefore, the bending allowable region D is mainly bent, and the proximal end side collapse is suppressed. Thus, in the catheter 10, the pulling operation of the pull wire 50 is not performed because the bending of the proximal end side of the tubular member 20 is suppressed by the tension generated in the bending suppression member 60 when the pulling operation of the pull wire 50 is performed. In some cases, the flexibility of the tubular member 20 can be maintained, and the tubular member 20 can be bent following the blood vessel.

  In order to selectively bend the bendable region D, the bendability (flexibility) of the bendable region D of the tubular member 20 is higher than the bendability of the tubular member 20 in the region proximal to the bendable region D. It is preferable to do. For example, it is preferable to use a material having a Shore hardness higher than that of the bending allowable region D in the region proximal to the bending allowable region D.

(Embodiment 2)
The catheter 10 according to the second embodiment is a bi-direction type in which the distal end portion can be deflected in both directions. FIG. 4 is a plan view of the catheter according to the second embodiment. FIG. 5 is a cross-sectional view along the line A′-A ′ shown in FIG. 4. In the present embodiment, the cross-sectional view of the tip portion along the line CC shown in FIG. 5 has the same structure as FIG.

  In the catheter 10 of the present embodiment, a third lumen (pull wire lumen) 24 is provided at a position symmetrical to the first lumen 22 with the central axis of the tubular member 20 as the axis of symmetry. In the present embodiment, the second lumen 23 is provided in the vicinity of the third lumen 24. The fourth lumen 25 is provided at a position symmetrical to the second lumen 23 with the central axis of the tubular member 20 as the axis of symmetry. The inner diameters of the third lumen 24 and the fourth lumen 25 are, for example, 0.2 to 0.6 mm.

  The pull wire (operation wire) 52 is inserted through the third lumen 24. Similar to the pull wire 50, the pull wire 52 is made of SUS wire, tungsten, a Ni—Ti superelastic alloy, or the like, and has a diameter of, for example, 0.1 to 0.5 mm. The distal end of the pull wire 52 is located near the distal end of the tubular member 20 and is fixed by an adhesive or solder (not shown). The proximal end of the pull wire 52 is connected to a rotation operation unit 34 for performing a deflection operation of the bending allowable region D of the catheter tube 10. By operating the rotation operation unit 34, the pull wire 52 is pulled, and the bending allowable region D is bent in the B direction shown in FIG. 1, whereby the distal end of the catheter 100 is deflected in the B direction opposite to the A direction.

  The bending suppression member 62 is inserted through the fourth lumen 25. As in the first embodiment, the bending suppressing member 62 is made of a wire resistant to tensile load such as SUS wire, tungsten, Ni-Ti superelastic alloy, and has a diameter of, for example, 0.1 to 0.5 mm. . The distal end of the bending suppressing member 62 is located on the proximal side by the length of the bending allowable region D from the position of the distal end of the pull wire 52, and is fixed by an adhesive or solder (not shown). Yes. The proximal end of the bending suppressing member 62 is located in the handle 30 and is fixed by an adhesive or solder (not shown). The bending suppression member 62 is stretched so as not to loosen.

  In the catheter 10 described above, during the pulling operation of the pull wire 50, a force that opposes the force with which the pull wire 50 tries to bend in the A direction is applied to the bending suppressing member 60 on the proximal side from the bending allowable region D. In addition, the entire tubular member 20 can be prevented from falling in the A direction while the bending allowable region D is bent in the A direction. Further, during the pulling operation of the pull wire 52, a force that opposes the force that the pull wire 52 tries to bend in the B direction is provided to the bend suppressing member 62 on the proximal side from the bend allowable region D. It is possible to prevent the entire tubular member 20 from falling in the B direction while curving the B in the B direction. That is, in the bi-direction type catheter 10, the entire tubular member 20 is suppressed from being collapsed when the deflection operation is performed in any direction. In the catheter 10 of the present embodiment as well, when the pulling operation of the pull wire 50 or the pull wire 52 is performed, the bending of the proximal end side of the tubular member 20 is suppressed by the tension generated in the bending suppressing member 60 or the bending suppressing member 60. Therefore, when the pulling operation of the pull wire 50 and the pull wire 52 is not performed, the flexibility of the tubular member 20 can be maintained, and it is possible to bend following the blood vessel.

Example 1
A bi-direction type catheter in which a bending suppressing member and a pull wire as shown in Embodiment 2 were incorporated was produced with the dimensions and materials shown in Table 1.

(Comparative Example 1)
A bi-direction type catheter incorporating only a pull wire was prepared with the dimensions and materials shown in Table 1.

For each of the catheters of Example 1 and Comparative Example 1, the collapse when the pull wire was pulled was evaluated. FIG. 6 is a diagram showing a method for evaluating the collapse of the catheter when the pull wire is pulled. When the pull wire is pulled to the maximum, the proximal end portion of the bending allowable region D, in other words, the position of the distal end portion of the non-curving region proximal to the bending allowable region D is the tubular member of the catheter when the pulling operation is not performed. The amount of deviation from the line L (the distance in the direction perpendicular to the line L) was measured as the amount of fall W. As a result, in Example 1, the amount of collapse W was 95 mm. On the other hand, in Comparative Example 1, the amount of collapse W was 220 mm. As described above, it was confirmed that the fall of the pulling operation was significantly suppressed in the catheter of Example 1 as compared with the catheter of Comparative Example 1.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added are also possible. It can be included in the scope of the present invention.

  For example, in each of the above-described embodiments, a catheter sheath is shown as an example of a catheter. However, a mechanism related to tip deflection is applicable to all catheters including electrode catheters. When there is no restriction to make the tube thin like a catheter sheath, the first to fourth lumens are arranged on a straight line passing through the center of the tubular member 20 in the bi-direction type shown in the second embodiment. May be.

  Further, in each of the above-described embodiments, the proximal end of the bending suppressing member is fixed in the handle, and in principle, the user cannot touch it. However, the screw head is exposed to the outside of the handle. It is good also as a structure which can adjust the tension | tensile_strength of a bending suppression member by winding the proximal end of a bending suppression member and turning a screw by a user.

  In the second embodiment, the bending suppression member 60 for applying a tension force that opposes the pull wire 50 and the pull wire 52 for the deflection operation opposite to the pull wire 50 are inserted through different lumens. 60 and the pull wire 52 may be inserted through a common lumen. Similarly, the bending suppression member 62 and the pull wire 50 may be inserted through a common lumen.

  In the second embodiment, the common bendable region D is set in the A direction and the B direction, but the bendable region may be different in the A direction and the B direction. According to this, in the bi-direction type catheter, it is possible to obtain an operational feeling that matches the blood vessel shape and the like.

  DESCRIPTION OF SYMBOLS 10 Catheter, 20 Tubular member, 21 Lumen, 22 1st lumen, 23 2nd lumen, 24 3rd lumen, 25 4th lumen, 30 Handle, 32 Rotation operation part, 34 Rotation operation part, 40 Tip, 50 Pull wire , 52 Pull wire, 60 Bending suppression member, 62 Bending suppression member, 70 Fixing part

Claims (5)

A flexible tubular member having a plurality of lumens formed along the axial direction;
Of the plurality of lumens, an operation wire inserted into an operation lumen disposed at a position deviating from a central axis of the tubular member and having one end fixed in the vicinity of the distal end of the tubular member. When,
Inserted into a curving suppression lumen disposed along the central axis on the opposite side of the central axis with respect to the central axis, one end of the operating wire is more than the one end of the operating wire A bending-suppressing wire positioned on the proximal side by the length of the bending-allowable region of the operation wire;
With
A distal end of the bending suppressing wire is fixed to the tubular member, and a proximal end of the bending suppressing wire is fixed to a handle provided on the proximal side of the tubular member;
A catheter, wherein a proximal end of the operation wire is fixed to an operation unit. Only the bending suppression wire is inserted through the bending suppression lumen,
The catheter according to claim 1, wherein the tubular member has a thickness of 0.3 to 1.0 mm. Inserted into another operating lumen disposed along the central axis on the side opposite to the operating lumen with respect to the central axis, and one end is fixed near the distal end of the tubular member Other operating wires
The other end of the other operation wire is inserted into another bending-suppressing lumen disposed along the center axis on the side opposite to the other operation wire with respect to the center axis. by the length of the curved allowable region of the other operating wire from one end and the other bending suppressing wire positioned proximally,
With
A distal end of the other bending restraining wire is fixed to the tubular member, and a proximal end of the other bending restraining wire is fixed to the handle;
The catheter according to claim 1 or 2, wherein a proximal end of the other operation wire is fixed to an operation unit.   The catheter according to claim 3, wherein only the other bending-suppression wire is inserted through the other bending-suppression lumen.   The catheter according to any one of claims 1 to 4, further comprising a lumen that is provided along the central axis in a region including the central axis and through which another catheter is inserted.

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